Abilities

You grab enemies, if you can't land this skill shot, you suck, you just plainly suck in general. This skill can win games by pulling enemies that are off guard, escaping, or just standing there looking stupid. This skill can also save teammates that are being focused by carries.

Spammables AoE silence. Use this to farm because of its short cool down, and during team fights use this to just be a general asshole to your enemies.

Items

Boots of Swiftness-Getting to where you need to faster is better as blitz, and this and your overdrive will make you faster than everyone else.

Manamune-Gives you attack damage based off of your mana, if you do not get this you are doing everything wrong. Extra mana = survivability. Extra attack damage = Less uselessness when your cool downs are on.

Frozen Heart-Another core item on blitz, the extra armor along with the +500 mana will just make you un-killable thanks to your passive. Along with the extra hp for your shield, the extra mana will work with manamune. AND DECREASES COOLDOWNS BY 20% WHICH LETS YOU SPAM YOUR ULT AND YOUR POWER FIST.

After those 3 core items you can build into a banshee's veil, thorn mail, sunfire cape. The last 3 items just depend whether the enemy team is caster heavy or not.

ITEMS NOT TO GET or
You gives are probably shitting yourselves, just thinking "NO LICH BANE OR TRINITY FORCE ON BLITZ WHAT IS THIS?!!?" But yeah you don't need it, your job is to tank, not to be able to dish out extra damage. A combination between getting manamune + frozen heart + your base mana should be already more than enough attack damage than you actually need. So yeah, don't waste your gold for that extra oomph of burst damage, just continue to build tanky items that give you armor/resists along with bonus mana.

Skilling Order

Maxing your pull will only increase its damage, and slightly decrease its cooldown. It is not needed at max first because you shouldn't be using it for its damage, just for how it can easily displace enemies and because of your items, the cooldown will not be a problem.

Leveling up overdrive will allow you to escape, chase, and deal out more damage with your auto attack or get into position for your power fist.

Power fist should be maxed out first because of how useful it is. The more you level it, the shorter its cool down will be, so that will allow you to be able to knock up your enemy every 4-5 seconds, and its increased double damage bonus will help you dish out terrible terrible damage.

Use your ultimate to farm creeps, and during team fights make sure you use its silence to cancel channel spells.